/**
 * @author       Richard Davey <rich@photonstorm.com>
 * @copyright    2020 Photon Storm Ltd.
 * @license      {@link https://opensource.org/licenses/MIT|MIT License}
 */

 var Class = require('../../utils/Class');
 var FileTypesManager = require('../FileTypesManager');
 var GetFastValue = require('../../utils/object/GetFastValue');
 var IsPlainObject = require('../../utils/object/IsPlainObject');
 var MultiFile = require('../MultiFile.js');
 var ScriptFile = require('./ScriptFile.js');
 
 /**
  * @classdesc
  * A Multi Script File suitable for loading by the Loader.
  *
  * These are created when you use the Phaser.Loader.LoaderPlugin#scripts method and are not typically created directly.
  *
  * For documentation about what all the arguments and configuration options mean please see Phaser.Loader.LoaderPlugin#scripts.
  *
  * @class MultiScriptFile
  * @extends Phaser.Loader.MultiFile
  * @memberof Phaser.Loader.FileTypes
  * @constructor
  * @since 3.17.0
  *
  * @param {Phaser.Loader.LoaderPlugin} loader - A reference to the Loader that is responsible for this file.
  * @param {(string|Phaser.Types.Loader.FileTypes.MultiScriptFileConfig)} key - The key to use for this file, or a file configuration object.
  * @param {string[]} [url] - An array of absolute or relative URLs to load the script files from. They are processed in the order given in the array.
  * @param {Phaser.Types.Loader.XHRSettingsObject} [xhrSettings] - An XHR Settings configuration object for the script files. Used in replacement of the Loaders default XHR Settings.
  */
 var MultiScriptFile = new Class({
 
     Extends: MultiFile,
 
     initialize:
 
     function MultiScriptFile (loader, key, url, xhrSettings)
     {
         var extension = 'js';
         var files = [];
 
         if (IsPlainObject(key))
         {
             var config = key;
 
             key = GetFastValue(config, 'key');
             url = GetFastValue(config, 'url');
             xhrSettings = GetFastValue(config, 'xhrSettings');
             extension = GetFastValue(config, 'extension', extension);
         }
 
         if (!Array.isArray(url))
         {
             url = [ url ];
         }
 
         for (var i = 0; i < url.length; i++)
         {
             var scriptFile = new ScriptFile(loader, {
                 key: key + '_' + i.toString(),
                 url: url[i],
                 extension: extension,
                 xhrSettings: xhrSettings
             });
 
             //  Override the default onProcess function
             scriptFile.onProcess = function ()
             {
                 this.onProcessComplete();
             };
 
             files.push(scriptFile);
         }
 
         MultiFile.call(this, loader, 'scripts', key, files);
     },
 
     /**
      * Adds this file to its target cache upon successful loading and processing.
      *
      * @method Phaser.Loader.FileTypes.MultiScriptFile#addToCache
      * @since 3.17.0
      */
     addToCache: function ()
     {
         if (this.isReadyToProcess())
         {
             for (var i = 0; i < this.files.length; i++)
             {
                 var file = this.files[i];
 
                 file.data = document.createElement('script');
                 file.data.language = 'javascript';
                 file.data.type = 'text/javascript';
                 file.data.defer = false;
                 file.data.text = file.xhrLoader.responseText;
 
                 document.head.appendChild(file.data);
             }
 
             this.complete = true;
         }
     }
 
 });
 
 /**
  * Adds an array of Script files to the current load queue.
  *
  * The difference between this and the `ScriptFile` file type is that you give an array of scripts to this method,
  * and the scripts are then processed _exactly_ in that order. This allows you to load a bunch of scripts that
  * may have dependencies on each other without worrying about the async nature of traditional script loading.
  *
  * You can call this method from within your Scene's `preload`, along with any other files you wish to load:
  *
  * ```javascript
  * function preload ()
  * {
  *     this.load.scripts('PostProcess', [
  *         'libs/shaders/CopyShader.js',
  *         'libs/postprocessing/EffectComposer.js',
  *         'libs/postprocessing/RenderPass.js',
  *         'libs/postprocessing/MaskPass.js',
  *         'libs/postprocessing/ShaderPass.js',
  *         'libs/postprocessing/AfterimagePass.js'
  *    ]);
  * }
  * ```
  *
  * In the code above the script files will all be loaded in parallel but only processed (i.e. invoked) in the exact
  * order given in the array.
  *
  * The files are **not** loaded right away. They are added to a queue ready to be loaded either when the loader starts,
  * or if it's already running, when the next free load slot becomes available. This happens automatically if you
  * are calling this from within the Scene's `preload` method, or a related callback. Because the files are queued
  * it means you cannot use the files immediately after calling this method, but must wait for the files to complete.
  * The typical flow for a Phaser Scene is that you load assets in the Scene's `preload` method and then when the
  * Scene's `create` method is called you are guaranteed that all of those assets are ready for use and have been
  * loaded.
  *
  * The key must be a unique String and not already in-use by another file in the Loader.
  *
  * Instead of passing arguments you can pass a configuration object, such as:
  *
  * ```javascript
  * this.load.scripts({
  *     key: 'PostProcess',
  *     url: [
  *         'libs/shaders/CopyShader.js',
  *         'libs/postprocessing/EffectComposer.js',
  *         'libs/postprocessing/RenderPass.js',
  *         'libs/postprocessing/MaskPass.js',
  *         'libs/postprocessing/ShaderPass.js',
  *         'libs/postprocessing/AfterimagePass.js'
  *        ]
  * });
  * ```
  *
  * See the documentation for `Phaser.Types.Loader.FileTypes.MultiScriptFileConfig` for more details.
  *
  * Once all the files have finished loading they will automatically be converted into a script element
  * via `document.createElement('script')`. They will have their language set to JavaScript, `defer` set to
  * false and then the resulting element will be appended to `document.head`. Any code then in the
  * script will be executed. This is done in the exact order the files are specified in the url array.
  *
  * The URLs can be relative or absolute. If the URLs are relative the `Loader.baseURL` and `Loader.path` values will be prepended to them.
  *
  * Note: The ability to load this type of file will only be available if the MultiScript File type has been built into Phaser.
  * It is available in the default build but can be excluded from custom builds.
  *
  * @method Phaser.Loader.LoaderPlugin#scripts
  * @fires Phaser.Loader.LoaderPlugin#ADD
  * @since 3.17.0
  *
  * @param {(string|Phaser.Types.Loader.FileTypes.MultiScriptFileConfig|Phaser.Types.Loader.FileTypes.MultiScriptFileConfig[])} key - The key to use for this file, or a file configuration object, or array of them.
  * @param {string[]} [url] - An array of absolute or relative URLs to load the script files from. They are processed in the order given in the array.
  * @param {string} [extension='js'] - The default file extension to use if no url is provided.
  * @param {Phaser.Types.Loader.XHRSettingsObject} [xhrSettings] - Extra XHR Settings specifically for these files.
  *
  * @return {this} The Loader instance.
  */
 FileTypesManager.register('scripts', function (key, url, xhrSettings)
 {
     var multifile;
 
     //  Supports an Object file definition in the key argument
     //  Or an array of objects in the key argument
     //  Or a single entry where all arguments have been defined
 
     if (Array.isArray(key))
     {
         for (var i = 0; i < key.length; i++)
         {
             multifile = new MultiScriptFile(this, key[i]);
 
             this.addFile(multifile.files);
         }
     }
     else
     {
         multifile = new MultiScriptFile(this, key, url, xhrSettings);
 
         this.addFile(multifile.files);
     }
 
     return this;
 });
 
 module.exports = MultiScriptFile;
 